I am aware that there are several questions concerning how much space to reserve on a filesystem using
tune2fs -m, but some of the advice is contradictory, some seems to be relevant only to the filesystem where
root is mounted, and none seems to be specifically for
The drive I'm enquiring about is a 3 TB hybrid SSD/Hard Disk with one partition formatted using
ext4 and which is ONLY used for media files.
swap are all in their own partitions on a SSD drive which I will be leaving well alone.
At the moment on the 3 TB
ext4 filesystem, 5% of disk space is reserved (the default), but that's a whopping 150 GB. If safe to do so I'd like to reduce this to 1%, which would be 30 GB, and in so doing free up 120 GB. Please note that the filesystem is 92% full, 5% of the remaining is the reserved space.
The advice in this answer, suggests that setting the reserved space to 5% is sensible on nearly full
ext3 filesystems to avoid fragmentation. It then states that
ext4 is more efficient, explicitly stating that: "ext4's multi-block allocator is much more fragmentation resistant". It does NOT then go on to advise what percentage would be sensible for
I'd like to know whether it would be safe to reduce the reserved drive space to 1% on my 3 TB
ext4 filesystem, while still maintaining adequate filesystem fragmentation protection?
If the 30 GB reserved space at 1% is not enough, then how little would be safe?